how to solve worcester boiler a21 fault?

[daxu]

hi,
My room thermostat is suddently showing A21 error, according to the manual, A21 fault code indicates no RF signal. But I can't find steps to solve this (I tried to restart the thermostat).
Is there a switch on the boiler to turn on/off RF singal or could this be a battery issue? (unlikely I am guessing)

Does anyone have experience?

thanks

 

[Madrab]

Take your thermostat off the wall and take it over to the receiver and see if it reconnects.
If not try new batteries.
Then try un-pairing and re-pairing (section 3.4.1 in your installation manual)

If it still doesn't work then the unit may have a fault and might need replaced.